The present invention relates to an absorbent article such as a disposable diaper, a urine absorbent pad, a sanitary napkin, or the like, particularly to an absorbent article having a surface structure material which is excellent in fitting property to a human body and which can effectively prevent side leakage.
A conventional absorbent article such as a disposable diaper, a urine absorbent pad, a sanitary napkin, or the like generally comprises a liquid-permeable top sheet, which faces the wearer and receives excrement in use, a liquid-impermeable back sheet and an absorbent core, which is interposed between the top sheet and the back sheet and absorbs the excrement permeated through the top sheet. The absorbent core is formed by pulp and SAP (super absorbent polymer) or the like.
Among these absorbent articles, there may be a relatively bulky cushion layer constituted by hydrophilic fibers is provided between the absorbent core and the top sheet, so as to improve fitting property to the urogenital organs or environs of the wearer when it comes into contact with the crotch region of the wearer and to prevent side leakage of excrement such as urine or menses blood.
However, because the shape of the crotch region differs from one individual to another, the absorbent article having the above-mentioned cushion layer does not necessarily provide a close fit in the crotch region.
Particularly in aged people, there are remarkable differences in the shapes of the crotch region (including the urogenital organs and the inguinal region) or the abdominal region or the region between the buttocks of individuals due to shrinking of the flesh, loosening or wrinkling of the skin accompanied by age. Thus, there are many cases that a disposable diaper, a urine absorbent pad, or the like for caring for aged people cannot provide a close fit in the crotch region, etc. Further, the amount of urination of an aged person per episode is much greater than that of a baby. Thus, if the disposable diaper or the urine absorbent pad does not provide a close fit in the crotch region, urine leaks from the sides thereof, which results in wet clothes or sheets.
The present invention is to solve the conventional problems as mentioned above, and an object of the present invention is to provide an absorbent article which is easily deformed and provide a close fit in the crotch region of the wearer to conform with the shape thereof and can prevent side leakage of excrement.
The present invention is to provide an absorbent article comprising a liquid-permeable top sheet, a back sheet, and an absorbent core interposed between the top sheet and the back sheet, wherein the top sheet rises upwardly from the absorbent core to have a plurality of protrusions, which extend parallel with one another in a longitudinal direction of the absorbent article, and a hydrophilic material is provided within the protrusions so as to form a cushion layer.
The absorbent article can be used as a disposable diaper, a sanitary napkin, a urine absorbent pad, or the like, and provide a close fit in the crotch region of the wearer by the cushion layer, thereby preventing side leakage of excrement.
In order to ensure retainment of the hydrophilic material in the protrusions, it is preferred that a liquid-permeable intermediate sheet is provided between the top sheet and the absorbent core, and the top sheet and the intermediate sheet are joined at valley portions between the protrusions.
In the above construction, when joining of the top sheet and the intermediate sheet at the valley portions is carried out at intervals along the longitudinal direction, the liquid-permeable property at the valley portions is increased.
Further, when the density of the cushion layer is 0.4 g/cm3 or less and the hydrophilic material is formed by hydrophilic fibers or hydrophobic fibers subjected to hydrophilic treatment, having a fineness of 1 denier or more, it becomes bulky, liquid-permeable and easily recovered or restored elastically when pressurized.
Furthermore, when the height dimension of the protrusions is 5 mm or more, the cushion layer is easily deformed depending on the shape of the crotch region of the wearer. Still furthermore, when the gap between adjacent protrusions, at the mountainsides thereof, is narrower than the width of the valley portions, excrement is easily absorbed by the protrusions.
For adapting to the shape of the crotch region, it is possible to enlarge the cross-sectional areas of the protrusions positioned near the center of the absorbent article (in a lateral direction perpendicular to the longitudinal direction) compared with the cross-sectional areas of the protrusions positioned near the sides of the absorbent article.
The back sheet is preferably liquid-impermeable.
Moreover, it is preferred that liquid barriers inferior in liquid-permeability to that of the hydrophilic material are provided inside of the protrusions along the longitudinal direction to substantially divide the hydrophilic material in two portions in the respective protrusions. Thus, excrement is easily spread to a wide range along the longitudinal direction and absorbed by the absorbent core.
This liquid barrier may be a resinous film or a hydrophobic nonwoven fabric, or else may be formed in such a manner that the intermediate sheet upwardly rises from the absorbent core, at the inside of the protrusions, or the top sheet downwardly hangs from the tops of the protrusions, at the inside of the protrusions.